We intend to acquire a precise knowledge of the structure and dynamic state of membrane components of normal erythrocytes, especially of membrane proteins, such as Band III and Spectrin-Actin, and of their interaction with other membrane components and intracellular substances. Erythrocyte membranes from hereditary spherocytosis patient will be studied in a similar manner in an attempt to reveal the intrinsic molecular abnormality of the diseased erythrocytes. The major physical methods for this study are saturation transfer electron paramagnetic resonance spectroscopy and spin-level induced nuclear relaxation magnetic resonance techniques. Conventional electron paramagnetic resonance and phosphorous nuclear magnetic resonance methods will also be used.